CN207850906U - A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy - Google Patents
A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy Download PDFInfo
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- CN207850906U CN207850906U CN201820298615.0U CN201820298615U CN207850906U CN 207850906 U CN207850906 U CN 207850906U CN 201820298615 U CN201820298615 U CN 201820298615U CN 207850906 U CN207850906 U CN 207850906U
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Abstract
The utility model provides a kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy.Resonant mode photoacoustic cell includes：Air inlet and gas outlet；Two groups of photoacoustic cell components are interconnected, and are symmetrically disposed in the both sides of the central axis of resonant mode photoacoustic cell, and every group of photoacoustic cell component includes：Surge chamber is arranged in the end of this group of photoacoustic cell component, and be connected with air inlet；Resonant cavity, setting are connected in surge chamber, and with surge chamber；First window is disposed therein the outside of the end of one group of photoacoustic cell component, so that incident light enters from first window in this group of acousto-optic pond component；Two sound transducers, the voice signal generated in two resonant cavities of two groups of photoacoustic cell components for detection under test gas respectively；Difference amplifier, input terminal are connected with the output end of two sound transducers, and the voice signal for detecting two sound transducers subtracts each other.The embodiment of the utility model improves the detection sensitivity of gas, is very suitable for the detection of trace gas.
Description
Technical field
The utility model is related to gas detection technology fields, more particularly to a kind of for the humorous of gas optoacoustic spectroscopy detection
Formula of shaking photoacoustic cell.
Background technology
In the fields such as monitoring harmful gases, vehicle exhaust monitoring and smart power grid fault monitoring, high sensitivity is detected
On-line detecting system demand it is increasing, with realize to CO, CO2、CH4、C2H2、 SO2、H2S and SF6Wait the high-precision of gases
Spend fast slowdown monitoring.Optoacoustic spectroscopy is a kind of spectral technique based on optoacoustic effect, it is that optical signal is efficiently converted into sound letter
Number, the ultimate density of gas is detected and be calculated to voice signal by microphone, is very suitable for trace gas measurement
And the non intrusive measurement field under complex background (multicomponent multiple types gas).
Generating source of the photoacoustic cell as photoacoustic signal is the core of photoacoustic spectroscopy system, the direct shadow of performance
Ring the sensitivity and stability to photoacoustic spectroscopy system.Gas photoacoustic cell is divided into two kinds of resonant mode and disresonance type.Resonance
Formula photoacoustic cell has the advantage of oneself, high modulating frequency to make the part being inversely proportional with frequency in terms of noise and coherent signal
Electronic noise reduces, in addition, self structure can make the noise sound of surrounding reach minimum.Compared with disresonance type photoacoustic cell, more
Detection suitable for environment trace gas.
Existing resonant mode photoacoustic cell shape has cylindrical, spherical and rectangular.According to the difference of standing wave distribution mode, cylinder
The resonance mode of shape photoacoustic cell can be divided into radial, angular, longitudinal.The viscous loss of radial resonance mode is minimum, and quality factor is most
Height, but cavity volume and resonant frequency are maximum.The quality factor of angular resonance mode is relatively low, generally 100 or so, is total to
Vibration frequency is also almost one times smaller than the radial resonance mode of same radius cavity.The quality factor of longitudinal resonance mode is minimum, in 10-
Between 80, cavity volume and resonant frequency are minimum.There is poor anti jamming capability in these resonant mode photoacoustic cells and signal-to-noise ratio is low etc.
Disadvantage.
Utility model content
One purpose of the utility model is to solve resonant mode photoacoustic cell in the prior art there are poor anti jamming capabilities
The technical issues of disadvantages such as low with signal-to-noise ratio.
Particularly, the utility model provides a kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy, including：
Air inlet for being passed through under test gas and the gas outlet for the under test gas to be discharged；
Two groups of photoacoustic cell components are interconnected, and be symmetrically disposed in the central axis of the resonant mode photoacoustic cell
Both sides, every group of photoacoustic cell component include：
Surge chamber is arranged in the end of this group of photoacoustic cell component, and is connected with the air inlet；
Resonant cavity, setting are connected in the surge chamber, and with the surge chamber；
First window is disposed therein the outside of the end of one group of photoacoustic cell component, so that incident light is from first window
Mouth enters in this group of acousto-optic pond component, so that the under test gas in this group of photoacoustic cell component expands and compresses another group
Under test gas in photoacoustic cell component；
Two sound transducers, for detecting the under test gas respectively described in two of two groups of photoacoustic cell components
The voice signal that resonant cavity generates；
Difference amplifier, input terminal are connected with the output end of described two sound transducers, and being used for will be described two
The voice signal that sound transducer detects subtracts each other, to obtain double voice signal.
Optionally, the ratio of the surge chamber and the cross-sectional area of the resonant cavity is more than or equal to 5:1.
Optionally, the shape of the resonant cavity is cylindrical, rectangular or spherical.
Optionally, the shape of the resonant cavity is cylinder, and the length of the resonant cavity is with the ratio of its diameter of section
More than or equal to 10:1.
Optionally, the resonant mode photoacoustic cell further includes：
Second window, with the first window be arranged on same group of photoacoustic cell component, and be arranged with first window
The outside of mouth this group of opposite photoacoustic cell component the other end of position.
Optionally, the resonant mode photoacoustic cell further includes pipeline, for being connected to two groups of photoacoustic cell components；
The air inlet and the gas outlet are arranged at the middle position of the pipeline.
Optionally, the photoacoustic cell inner surface is coated with gold or silver.
Optionally, the sound transducer is mounted on the middle position of the resonant cavity.
Optionally, the opening of the sound transducer is arranged to flush with the tube wall of the resonant cavity.
Optionally, the sound transducer is microphone, piezoelectric ceramic microphone or fibre-optical acoustic sensor.
According to technical solutions of the utility model, by designing two groups of photoacoustic cell components, and only to one of which photoacoustic cell group
Part carries out illumination, so that the under test gas in the photoacoustic cell component is expanded, the under test gas quilt in another group of photoacoustic cell component
Compression so that the gas in two resonant cavities of two groups of photoacoustic cell components generates the voice signal of opposite in phase, and passes through
Difference amplifier obtains double voice signal after subtracting each other, which thereby enhance the detection sensitivity of gas, be very suitable for trace gas
Detection.In addition, two resonant cavities of the utility model are all made of longitudinal mode of resonance, quality factor is big, and detection sensitivity is high.
According to the accompanying drawings to the detailed description of the utility model specific embodiment, those skilled in the art will be more
Add the above-mentioned and other purposes, advantages and features of clear the utility model.
Description of the drawings
Some specific realities of the utility model are described in detail by way of example rather than limitation with reference to the accompanying drawings hereinafter
Apply example.Identical reference numeral denotes same or similar component or part in attached drawing.It should be appreciated by those skilled in the art that
The drawings are not necessarily drawn to scale.In attached drawing：
Fig. 1 is that the resonant mode photoacoustic cell according to the utility model one embodiment for gas optoacoustic spectroscopy detection shows
Meaning property structure chart.
Drawing reference numeral：1- air inlets, the gas outlets 2-, 3- the first photoacoustic cell components, the first surge chambers of 31-, 32- first are humorous
Shake chamber, 4- the second photoacoustic cell components, the second surge chambers of 41-, the second resonant cavities of 42-, 5- first windows, the first sound sensors of 6-
Device, 7- second sound sensors, 8- difference amplifiers, the second windows of 9-.
Specific implementation mode
Fig. 1 shows the resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy according to the utility model one embodiment
Schematic diagram.The resonance mode of the resonant mode photoacoustic cell is longitudinal resonance mode.As shown in Fig. 1, the resonant mode optoacoustic
Pond includes air inlet 1,2, two groups of gas outlet photoacoustic cell component, 5, two sound transducers of first window and difference amplifier 8.
In one embodiment, the cross sectional shape of the resonant mode photoacoustic cell is " I " fonts.Two groups of photoacoustic cell components include
Interconnected the first photoacoustic cell component 3 and the second photoacoustic cell component 4.First photoacoustic cell component 3 and the second photoacoustic cell component 4
It is symmetrically disposed in the both sides of the central axis of the resonant mode photoacoustic cell.First photoacoustic cell component 3 includes the first surge chamber 31
With the first resonant cavity 32.First surge chamber 31 is arranged in the end of the first photoacoustic cell component 3, and is connected with air inlet 1.First
The setting of resonant cavity 32 is connected in the first surge chamber 31, and with the first surge chamber 31.Second photoacoustic cell component 4 includes second slow
Rush room 41 and the second resonant cavity 42.Second surge chamber 41 is arranged in the end of the second photoacoustic cell component 4, and is connected with air inlet 1
It is logical.The setting of second resonant cavity 42 is connected in the second surge chamber 41, and with the second surge chamber 41.In one embodiment,
It is connected by a pipeline between one surge chamber 31 and the second surge chamber 41, and is connected to air inlet 1 simultaneously.
Wherein, air inlet 1 and gas outlet 2 can be arranged on the pressure node of sound standing wave, such as can be arranged above-mentioned
The middle position of pipeline.At this position, sound field is most weak, can be to avoid gas in photoacoustic cell flows and causes noise.
First window 5 is arranged in the outside of the first end of the first photoacoustic cell component 3, can specifically be arranged in the first buffering
The outside of room 31, for making incident light enter in the first acousto-optic pond component from first window 5.Two sound transducers respectively include
First sound transducer 6 and second sound sensor 7.First sound transducer 6 is for detecting under test gas in the first resonant cavity
The voice signal generated in 32.Second sound sensor 7 is used to detect the sound that under test gas generates in the second resonant cavity 42
Signal.First sound transducer 6 and second sound sensor 7 for example can be microphone, piezoelectric ceramic microphone or optical fiber sound
Sensor.The output end of first sound transducer 6 and second sound sensor 7 is connected with the input terminal of difference amplifier 8.
In one embodiment, which further includes the second window 9.Second window 9 is arranged in the first optoacoustic
On the outside of the second end of pond component 3, the second end of photoacoustic cell component is located at its first end on opposite position.
Infrared light supply enters from first window 5 in photoacoustic cell, and the under test gas in the first photoacoustic cell component 3 absorbs infrared light
Behind source, heat is generated by the excitation of light, to expand, under test gas in the second photoacoustic cell component 4 due to not by
Illumination, therefore gas expansion does not occur in moment.Therefore, the second light is compressed after the gas expansion in the first photoacoustic cell component 3
Gas in sound pond component 4, so that the phase of the voice signal generated in the first resonant cavity 32 and the second resonant cavity 42 is
Opposite, the transmission of sound signals for then detecting the first sound transducer 6 and second sound sensor 7 is to difference amplifier
8, difference amplifier 8 subtracts each other two voice signals, to obtain double voice signal.
Scheme according to the present utility model, by designing two groups of photoacoustic cell components, and only to one of which photoacoustic cell component
Illumination is carried out, so that the under test gas in the photoacoustic cell component is expanded, the under test gas in another group of photoacoustic cell component is pressed
Contracting so that the gas in two resonant cavities of two groups of photoacoustic cell components generates the voice signal of opposite in phase, and passes through difference
Double voice signal is obtained after dividing amplifier 8 to subtract each other, the detection sensitivity of gas is which thereby enhanced, is very suitable for trace gas
Detection.In addition, two resonant cavities of the utility model are all made of longitudinal mode of resonance, quality factor is big, and detection sensitivity is high.
In one embodiment, the ratio between cross-sectional area of the first surge chamber 31 and the first resonant cavity 32 for example can be 5:1、
6:1、7:1、8:1 or 9:1, can also be more than 5:1 any other ratios.Since the photoacoustic signal of under test gas can be by
The influence of the relevant noises such as the noise that one window 5 generates light absorption, and the loudness decaying of photoacoustic signal is and resonant cavity
Cross-sectional area be inversely proportional.By rationally designing the structure type of two groups of photoacoustic cell components, and pass through lot of experiment validation, the
The ratio between cross-sectional area of one surge chamber 31 and the first resonant cavity 32 is greater than or equal to 5:When 1, the first surge chamber 31 is to the noise that is concerned with
Isolation effect it is preferable.It is less than 5 in the ratio between cross-sectional area of the first surge chamber 31 and the first resonant cavity 32:When 1, the first surge chamber
The isolation effect of 31 pairs of relevant noises is poor.The ratio between second surge chamber 41 and the cross-sectional area of the second resonant cavity 42 are also greater than
Or it is equal to 5:1 any ratio, reason can refer to the ratio between cross-sectional area of the first surge chamber 31 and the first resonant cavity 32 and choose
The reason of, details are not described herein again.
In addition, the first resonant cavity 32 and the second resonant cavity 42 can be fabricated to cylindrical, rectangular or spherical, preferably cylinder
Shape.When the first resonant cavity 32 is cylindrical, the length of the first resonant cavity 32 and the ratio of its diameter of section can be more than or
Equal to 10:1 any ratio, such as 10:1、11:1、12:1、13:1 or 15:1.In resonant cavity, the master of optoacoustic wave attenuation is caused
It is the viscous and heat transfer on resonance inner cavity surface to want one of reason.By the way that the structure of resonant cavity is rationally arranged, and according to structure
The ratio of rational length and diameter of section is set to increase the intensity of photoacoustic signal in resonant cavity.The knot of second resonant cavity 42
The ratio of structure, length and diameter of section is consistent with the first resonant cavity 32.
The inner surface of the resonant mode photoacoustic cell needs to polish, and vapor deposition has gold or silver.This can reduce photoacoustic cell inner wall pair
The absorption of incident light and the generation of solid optoacoustic effect, while the viscous caused loss of pool wall is reduced, and can make photoacoustic cell
Absorption to gas and desorption very little.
The centre position of the first resonant cavity 32, and the opening of the first sound transducer 6 is arranged in first sound transducer 6
It is arranged to flush with the inner wall of the first resonant cavity 32, for obtaining the voice signal that under test gas generates in the first resonant cavity 32.
The centre position of the second resonant cavity 42 is arranged in second sound sensor 7, and the opening of second sound sensor 7 is arranged to and the
The inner wall of two resonant cavities 42 flushes, for obtaining the voice signal that under test gas generates in the second resonant cavity 42.By the first sound
The centre position of the first resonant cavity 32 is arranged in sensor 6, and second sound sensor 7 is arranged to the interposition of the second resonant cavity 42
It sets, can more efficiently get photoacoustic signal in this way.
So far, although those skilled in the art will appreciate that the more of the utility model have been shown and described in detail herein
A exemplary embodiment still, still can be according to the utility model public affairs in the case where not departing from the spirit and scope of the utility model
The content opened directly determines or derives many other variations or modifications for meeting the utility model principle.Therefore, this practicality is new
The range of type is understood that and regards as to cover other all these variations or modifications.
Claims (9)
1. a kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy, which is characterized in that including：
Air inlet for being passed through under test gas and the gas outlet for the under test gas to be discharged；
Two groups of photoacoustic cell components are interconnected, and are symmetrically disposed in the both sides of the central axis of the resonant mode photoacoustic cell,
Every group of photoacoustic cell component include：
Surge chamber is arranged in the end of this group of photoacoustic cell component, and is connected with the air inlet；
Resonant cavity, setting are connected in the surge chamber, and with the surge chamber；
First window is disposed therein the outside of the end of one group of photoacoustic cell component so that incident light from the first window into
Enter in this group of photoacoustic cell component, so that the under test gas in this group of photoacoustic cell component expands and compresses another group of optoacoustic
Under test gas in the component of pond；
Two sound transducers, for detect respectively the under test gas two groups of photoacoustic cell components two resonance
The voice signal that chamber generates；
Difference amplifier, input terminal are connected with the output end of described two sound transducers, are used for described two sound
The voice signal that sensor detects subtracts each other, to obtain double voice signal.
2. resonant mode photoacoustic cell according to claim 1, which is characterized in that the surge chamber is transversal with the resonant cavity
The ratio of area is more than or equal to 5:1.
3. resonant mode photoacoustic cell according to claim 1, which is characterized in that the shape of the resonant cavity is cylindrical, side
Shape or spherical shape.
4. resonant mode photoacoustic cell according to claim 3, which is characterized in that the shape of the resonant cavity is cylinder, institute
The ratio of the length for stating resonant cavity and its diameter of section is more than or equal to 10:1.
5. resonant mode photoacoustic cell according to claim 1, which is characterized in that further include：
Second window, with the first window be arranged on same group of photoacoustic cell component, and be arranged with the first window position
Set the outside of this group of opposite photoacoustic cell component the other end.
6. resonant mode photoacoustic cell according to claim 1, which is characterized in that further include pipeline, for being connected to described two groups
Photoacoustic cell component；
The air inlet and the gas outlet are arranged at the middle position of the pipeline.
7. resonant mode photoacoustic cell according to claim 1, which is characterized in that the sound transducer is mounted on the resonance
The middle position of chamber.
8. resonant mode photoacoustic cell according to claim 7, which is characterized in that the opening of the sound transducer be arranged to
The tube wall of the resonant cavity flushes.
9. the resonant mode photoacoustic cell according to any one of claim 1-8, which is characterized in that the sound transducer is micro-
Sound device, piezoelectric ceramic microphone or fibre-optical acoustic sensor.
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| CN201820298615.0U CN207850906U (en) | 2018-03-02 | 2018-03-02 | A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy |
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| CN201820298615.0U CN207850906U (en) | 2018-03-02 | 2018-03-02 | A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108226050A (en) * | 2018-03-02 | 2018-06-29 | 苏州感闻环境科技有限公司 | A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy |
| CN111413281A (en) * | 2020-04-14 | 2020-07-14 | 大连理工大学 | High-sensitivity telemetering type gas sensor |
| CN112964299A (en) * | 2021-02-09 | 2021-06-15 | 中北大学 | High-temperature and high-pressure resistant structure heat-sound-vibration three-parameter integrated in-situ sensor and system |
| CN114965872A (en) * | 2022-04-27 | 2022-08-30 | 重庆科技学院 | Multi-sensor data fusion electronic nose and method |
-
2018
- 2018-03-02 CN CN201820298615.0U patent/CN207850906U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108226050A (en) * | 2018-03-02 | 2018-06-29 | 苏州感闻环境科技有限公司 | A kind of resonant mode photoacoustic cell for the detection of gas optoacoustic spectroscopy |
| CN111413281A (en) * | 2020-04-14 | 2020-07-14 | 大连理工大学 | High-sensitivity telemetering type gas sensor |
| CN112964299A (en) * | 2021-02-09 | 2021-06-15 | 中北大学 | High-temperature and high-pressure resistant structure heat-sound-vibration three-parameter integrated in-situ sensor and system |
| CN112964299B (en) * | 2021-02-09 | 2022-10-25 | 中北大学 | High-temperature and high-pressure resistant structure heat-sound-vibration three-parameter integrated in-situ sensor and system |
| CN114965872A (en) * | 2022-04-27 | 2022-08-30 | 重庆科技学院 | Multi-sensor data fusion electronic nose and method |
| CN114965872B (en) * | 2022-04-27 | 2023-10-13 | 重庆科技学院 | Electronic nose and method for multi-sensor data fusion |
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